Method of attaching soles to shoes



April 17, 1945. I w ow 2,373,922

METHOD OF ATTACHING SOLES TO SHOES Filed May 11, l9 44 4 Sheets-Sheet l April 17, 1945, M. w. TETLOW METHOD OF ATTACHING SOLES TO SHOES Filed May 11, 1944 4 Sheets-Sheet 2 April 17, 1945. M w TETLOW I 2,373,922

METHOD '01-" ATTACHING SOLES TO SHOES Filed May 11, 1944 4 Sheets-Shet 4 HEAT CONTENT mo OF 4000 MOIST AIR e TO ('8 0 o 6p 7/.1 e22 (93.3- nue 7 Max Wire-blow F1Z9 I By ttorney Q U -weer .outsoles have stood over night;

Patented Apr. 17, 19 45 rm'rnonorn'rmonmo soLEs'rosnoEs f I ,MaxfW. Tetlow, Sharon,.Mass., asSig nOrto BQBP I1Chemical 00., Boston, 'Mass fai'cotporation of Massachusetts Application May-11, 1944,. Seri ai No, 535,625.

e 10 Claims; (01. 1g- -142) Thisinvention relates to shoe-manufacture and I process of attaching outsoles to' shoe uppers by means of polymerized chloroprene. In said pat-. entedprocess, the outsole and the shoe upper are brought together under sole attaching pres sure While the polymerized chloroprene'previously applied to said shoe parts is in adhesive ccnditionwhich may be from about one, to six hours:

or more after the application of'the polymerized chloroprene cement .In the practice of such proc essythe sole-cementing; andother shoe factory .operationsjmust be timedwithin reasonably close limits in ordertha-t the cement on the outsoles maybe in an adhesive condition when'the uppers are ready for sole attaching Furthermore, with such process it is necessaryto seethat' the out soles are attached during the same Workin'gday that they are coated with cement because ordinarily the adhesiveness of the cement thereon is considerably reduced after the cement-coated In United States LettersPatent No. 2,087,878, granted July 20', 1937, upon" the a plication of Walter 1-1.; Wedger, there is describedfan improvement over the earlier Wedger patent wherein polymerized chloroprene on the outsolewhich has lost itsadhesiveness in substantial degree is temporarily restored to normal adhesiveness. and

the operation of attaching the outsile to theshoe more particularly to the-permanent attachment sole will spring back'upon release of the soleattaching pressure due to the normal resilience inherentfin,dry sole leather, and the margin of I the sole wrapped up over-the feather line of the shoe by'the conformable pad. of the-usual attaching press will tend to returnto its initial positionwhen'the pressure is relieved. 'The result is I that the polymerized 'chloroprene' cement is stretched slightly to form a great number of short threads spoken or as legs which appear as a heavy line in the creasetof the shoe between the marginalportions of the sole and upper; To

' it substantially inert.

make a short time dwell effective for proper sole attachment and to avoid the above-mentioned leggy condition it is necessarythat the sole be attached while in sufficient temper to render Objectsof' thepresent'invention are to provide iinprovements in the processor attaching outsol'es to shoe uppers with polymerized chloroprene'whereby the use of organic liquids for temporarily restoring the cement to adhesiveness may be eliminated, whereby the leather of the soles maybebrought into a substantially uniform and desirable condition of temper or inertness for the sole-attaching operation and whereby the cemented soles may be activated substantially-irrespectively of the lapse oftime since they were cemented, that is, Within a weekor, more.

A further ,objectis to condition the leather of the soles adequately for the sole-attaching operation 'without requiringunneces'sarydelay in car rying, out subsequent shoe manufacturing operations.

I In the accomplishment-of the above and other objects, I have discovered that polymerized chloroprene. coated leatherioutsoles wherein the ceupper performed while the outsole is in such coh- .dition' of temporary restoration to adhesiveness.

This temporary restoration to normaladhesiveness is accomplished by applying'to theisurface of the polymerized chloroprene cement on the ment has driedbeyond the tacky stage maybe successfully treated with" water-vapor laden air of certain characteristics. to activate the cement and simultaneously to inert the leather of the [sole sufliciently for sole attaching, the water vaoutsole before said polymerized chloroprene has become entirely cured'a material which'may be selected from certain organic liquids which'will por, content, contrary: toexpectation,v having no i deleteriouspefiect on the cement bondobtained;

swell and activate the cement. When the poly merized chloropreneis in attaching condition,

that: is to say, when the excess. or a'rnajor por tion of the swelling material has been dissipated but the plastic polymer is still inswelled condition, the outsole andshoe upper are brought into juxtapcsitionand placed under attaching pressure;

If the sole-attachit tl IOD rati on is carried out while the leather is not .temper"ordry, the

The atmosphere to which thesole-is subjected in. accordance with .this invention conforms .to all of the. following requirements, namely, it is laden with water vapor at atemperature in the neighborhood of 140 F. to 206?;F is of 50% to 100% relative humidity, andhas a heat content of from 200m 700 B. t. u. per pound of dry. air.

In carrying out myinvention, therefore, .a solution-cf polymerized chloroprene. is applied to the attaching surface of aleather outsole and a. major portion of the solvent is allowed to evaporate. An

atmosphere is provided which is at a temperature in the neighborhood of from 140 F. to 206 E, which is laden with water vapor to the extent of 50% to 100% relative humidity, and which has a heat content of from 200 to 700 B. t. u. per pound of dry air. The outsole is subjected to such an atmosphere for a time suficient to activate the cement, which may be, for example, from ten to sixty seconds, whereupon the outsole is immediately brought into juxtaposition with a shoe upper whose attaching surface isprovided with a layer of polymerized chloroprene. The outsole and shoe upper are then pressed firmly together.

In referring to the hot air as vapor laden, the word vapor is to be understood in its technical sense, that is, as indicating that the water is in a gaseous phase and substantially unmixed with water in the liquid phase.

In the practice of this invention, the cement is activated in avery short time, namely in as little as ten seconds. Simultaneously the leather of the sole is rendered substantially inert. The soleattaching pressure may be relieved in a very short time, for example, after a dwell of as little as five to eight seconds.

The practice of the invention ishighly advantageous in that the cement is uniformly activated and therefore better contact and more uniform adhesion to the shoe bottom may be obtained. Furthermore, the expense of providing and handling toxic solvent for activation is avoided. Moreover, the strength of the adhesive bond develops so rapidly that the use of a two-station machine is rendered feasible with resulting economy in the cost of machinery for sole attaching.

Where air of substantially 100% humidity is to be employed in the practice of the invention, I prefer to employ sole-treating apparatus such as that disclosed in United States Letters Patent No. 2,334,232, granted Novemberlfi, 1943, upon the application of Adoniram J. Wells. Where air of substantially less than 100% humidity is employed for the practice of the invention, a modified form of apparatus shown in Figs. 6 and 7 of this application may be employed, and indeed, even where air of substantially 100% humidity content is to be used the modified form of apparatus may be used.

In the drawings,

Fig. l is a perspective view showing the attaching face of an outsole that has had its marginal portion roughened, has had cement applied to the rou hened portion except at its extreme outer edge, and has been conformed;

Fig. 2 is a perspective view of a shoe the overlasted portion of the upper of which has been roughened and has had cement applied thereto; it shows also a shank piece and filler;

Fig. 3 is a view, partly in section, showing a shoe and its sole held under pressure on a conformable pad;

Fig. 4 is a sectional view of apparatus for treating the sole to activate the cement and cause the sole to become inert;

Fig. 5 is a sectional detail of a completed shoe;

Fig. 6 illustrates a modified form of apparatus to be used in practising the invention by which the relative humidityin the sole-treating chamber may be varied and controlled;

Fig. 7 is a front elevation, partly broken away, of the upper part of the apparatus; and.

Fig. 8 is a chart showing the heat content of moist air and illustrating the conditions of tem-v perature, humidity and heat content contemplated by the invention.

In carrying out this invention in a preferred manner, a leather sole l0 (Fig. 1) is rounded and its shank reduced at l2. The marginal portion M of the sole is next roughened and at that time it should be dry, that is, should contain not over five to ten per cent of moisture, that being regarded as a dry condition. The sole is therefore insufficiently in temper to be inert.

Good results have been obtained by applying to the marginal portion I4 of a dry sole polymerized chloroprene cement of substantially the composition disclosed in the Wedger Patent No. 2,087,878 hereinbefore referred to. It is to be understood, however, that other cements composed wholly or in part of rubber or synthetic rubber-like materials may be employed.

The cement may be applied by hand but better results are obtained by a sole-cementing machine such as that disclosed in Letters Patent of the United States No. 2,073,647, granted March 16, 1937, on an application filed in the name of Carl A. Newhall, by which the cement may be accurately.applied, leaving the extreme outer portion I 6 of the margin uncemented. The cement is indicated by stippling [8 in Fig. 1.

In Fig 2 is represented a shoe 20 on a last 22. The upper 20 of the shoe is lasted over an insole 26 in any usual manner. The overlasted marginal portion of the upper is roughened and cemented, the roughening being indicated by parallel lines at 28 and the cement by stippling at 30. The cement, which is likethatapplied to the sole, may be applied by hand with a brush. It is preferable, however, to employ mechanical means such, for example, as is disclosed in Letters Patent of the United States No. 2,100,341, granted November 30, 1937, on an application filed in the name of W. L. MacKenzie, or in Letters Patent of the United States No. 2,177,666, granted October 31, 1939, on an application filed in the names of W. L. MacKenzie and E. S. Nokes. About one hour should be allowed to elapse after application of the cement to the sole or shoe before the cement on the sole is activated for attachment to the shoe. The cement on the shoes, after drying, remains in condition for activation and attachment by the present method for a long time and on the soles even for a materially longer time.

Activation of the cement by heat and conditioning of the sole for attachment to the shoe are effected in an apparatus similar to that disclosed in the hereinbefore-mentioned Well patent which, as illustrated in Fig. .4, comprises a casing 36 which is closed except at the top where it is provided with slides 38 which may be opened for introduction of the soles and then partially closed. The soles H! are supported in the casing by two series of crossed wire 40, 42 at their lower ends and by other crossed wires 44, 46 betweenth'eir ends, still other crossed wires 48, 50 being provided at'the upper ends of the soles. The soles are thus held separated so that both surfaces of each sole irmnersed in. the Water is arranged an electric, immersion heating unit 60 'whichheats the water,

1 the. temperature of the vapor-laden air beingindi sated by a thermometer 62 located thevapor:

laden air passing, ,up throughgthercasing to; the upper portion thereof where the -soles H] are located, In theorising 36 at about the samelevel as the; thermomenter 6-2 isan adjustable thermostatzfikby which the temperature of. the vaporen air is controlledand maintained at a predetermined. point.

In order that. thevapor-laden air maybe subtime to the heat .activationhas. no deleterious acon the bond. obtained because. twenty seconds issufiicient tolbring the-temperature of'the cement up to the "activating temperature for which theapparatusis set and: its temperature will increase but slowly if it stays; longer in the apparatus while the absorption or the vapor bythesole: is progressive, since the longer it stays in the apparatus the more water vapor it absorbs though therate of absorption diminishes. V

Any suitableshoe press may be-employed. for

attaching the shoe and sole but excellent results stantially freefrom water ina liquid state, there is. provided between the water level 58' and. the

sole-supportingwires .40, 42 a series; of bafiles shown as a. pair; of. perforated. plates 66,; t8 spaced from" each other, the holes 10 in. one'platebeing' in staggered relation. tonthe holes 12 in. the other.

The baffles catch any water. globulesv caused by the splashing or spraying of the water by the passage of the air through it. The holesallow the. water to: return by gravity to the lower part of the casing and permit the passage of the vapor-ladenair through them. For this purpose the holes. are suificiently large to avoid any capillary effect.

The slides 38 are soradjustecl that the opening between. them will permit the. passage. of the volume of air introduced through thetubes. 54 and a .so that there will be an outward current of hot vapor laden air through theopening. .Even when the. slides are moved farther apart temporarily to permit the introduction of another sole the outward. current will prevent exterior relatively cold and dry, air' fromentering the. casing to. condense and liquefy the vapor. 4:-

While the temperature of the vapor-laden air may be. varied from 154 h; to172 F. to meet different conditions, it may be assumed, for example, that' thetemperature of the vapor-laden air isset for. 15493., that treatmentof a sole in the apparatusfortwenty seconds at 154 F. will activate the cement, and that the sole isin such condition that in that time it will simultaneously be rendered comparatively limp by the vapor treatment. The operator will :then'place a sole in they apparatus thr'oughthe opening'between the slides 38- and after ten seconds will place another-:sole in the apparatus. 'Then, after ten seconds, he; will remove-the first sole and insert a third.- The first sole. .is immediately placed in proper relation to the shoe 205, both being located on a. sole-pressing pad l0 and pressure applied to the shoe. through abutments 12;, .14 which engage respectively the forepart of the shoe and-the top of the cone of the last 22., This operation requires about ten seconds. and it is: then time to introduce a fourth. sole in the apparatus'and remove the second for attachment to. its shoe. which is done onv a second pressing: apparatus located beside the first. The first-shoe is now released, a fifth sole placed in the apparatus and the thirdsole re- 4 moved. for attachment on. the first press which is now free. This procedurefallows each sole to be subjected to theaction. of thehot vapor-laden all I tor thev requiredv time (twentyseconds) and enables. the operator toattach a sole every ten secends, each sole being leftunder pressure for ten seconds or longer. I

If the condition. of thesoles is such as to moisture content or as .to natural resistanceof the leather that a longer treatment inthe hot. vapor-.

laden air isdesirableto put itfin proper condition for attachment to a shoe, the operator'has only to keepthree or=moresoles in the apparatus: instead or two. The subjection of the cement fora. longer uniform pressure applied tothe shoe by inflation of the pad. insures that all parts of the sole will be forced against-the shoe bottom-about its periphery. [The initial pressure of the abutments 12., insures that the. shoe will be pressed against the: sole to shape the pad 10' to the shoe bottom and, prevent relative, movement of the shoe and. sole, while the uniform pressure, applied by inflation of they pad 16 to, force the sole against the shoe insures that all portions of the periphery will be brought into conformity to theshoe and sole and thattheformation of the desired feather line at the juncture of the sole and upper will be obtained, The resultingshoe is indicated: in the sectionalview of Fig. '5 where it'will be'seenfthat themarginalportion; of. the. sole is turned up in proper-relation to the feather line of the shoe- Activation at-the press, as is done by the present method, has distinct, practical advantages over the; prior sol-vent activation}whichv must be done an hour or more before placing. the shoe 4 and solein juxtaposition andapplying pressure.

since they sole; after activation, is immediately applied to the shoe and pressed thereon, the troublesome necessity of activation at a predetermined time prior to sole attachment is obviated. I q

Should the method described beunsatisfactory or faiLbecause of hardness ofithe. leather, toproduce the desired edge contourofthe sole, the sole, either before or after conforming, may be subjected to-an edge-turning operation in accordance with the method disclosed inv Letters Patent of the United States No. 2,209,406, granted July 30, 1940, on an, application of William P. Le Rette. By this method, a sole of refractory or insufiiciently tempered leather may have the resistance to bending and the resiliency of its. marginal portion so reduced that. it. will conform to the desired shoe bottom contour" and, remain substantially in the shape imparted to it unclersole-attaching pressure. It is to be understood that the sole-conforming and edge-turning operations herein referred to as desirable under certain conditions are not essential and that soles of :leather of some tannages and containing sufiicient moisture, say ten to twelve per cent, may be satisfactorily attached by the present method when subjected to the action of hot vapor-laden I air in a flat condition.

- In the apparatus. above describedthe relative humidity of. the: atmosphereirr which the soles in the sole-treating atmosphere.

(c) The relative humidity of the activating atmosphere;

(d) The amount of water in the sole, that is, its dryness;

(e) The grade of the sole, that is, whether the leather is hard or soft; and

(f) The initial temperature of the sole.

The first three conditions should be handled in the appratus; the others are independent of the apparatus but conditions (e) and (d) may be taken care of by varying (a), (b) and (c) The rate of heating of the sole and the cement thereon and the rate of absorption of moisture by the sole depend on the number of heat units Each unit of water, in passing from the liquid to thegaseous state at the same temperature, absorbs a large .number of heat units and conversely, in passing from a gaseous to a liquid state, it gives'up a large number of heat units without change of temperature.

The amount of heat in a vapor-laden atmosphere is usually expressed as the number of British thermal units per pound of dry air computed from the abritrary reference level of dry air at F. The chart 8 showsthe number of'British thermal units in moist air at different .conditions of temperature and relative humidity, and the area between the 100% R. H. line and the 50% R. H. Line, limited at the bottom by the 200 B. t. u. line and at the top by the 700 B. t.'u. line, indicates the variations of these three factors which are available for the practice of the present method. This area is enclosed by a heavy line on the chart.

In the following table the first two columns.

1 Temperature P ercent R. H B. t. 11.

C. l F.

In carrying out the present method, in which the sole-treating atmosphere is varied by controlling the temperature of the vapor-laden atmosphere. between 140 F. and 206 F., varying of the relative humidity from 50%-to 100% and varying of the British thermal units in the atmosphere from 200 to 700, the following apparatus may be employed. I

' A chamber I00 containing thesole-treating atmosphere is in the upper portionof a casing I02 in the front of which is a series of, vertical slots I04 (Fig. '7) through each of which a sole may be passed endwise into the chamber I00. The width of the slots I04 is such that the soles will be held substantiallynpright, their lower edges being supported by wires lflfi'extending across the bottom of the sole-treating chamber I00. The top of the chamber is closed by a hinged lid I08 having a handle IIO by which it may be lifted to inspect the interior of. the casing. As shown in Fig. 7, the inner surface of the lid I08 is cylindrical so that any moisture condensing on that surface will not drip. on the soles but will tend to run toward the sides of the casing. The top, side and rear walls of the casing are covered with insulating material II2. Just below the wires I00 is a thermometer H4 which indicates the temperature of the sole-treating atmosphere as .it enters the chamber I00. Below the thermometer is a baffle plate H0 similar to the plate 80, the plate IIB extending across the casing and being providedwith several lines of quarter inch openings spaced about one-half inch apart. Below the plate I16 is a pipe II 8 which, along its upper side, is provided with a series of small openings (for example s 5 of an inch) arranged about one-half inch apart. The pipe H8 is connected by a union I20 to a pipe I22 which is connected through a valve I24 to the delivery end of a heating coil I26 immersed in an oil bath contained in a suitable vessel I28. The entering end I30 of the coil is connected to a suitable source of compressed air. The oil in the vessel I28 is heated by an electric immersion heating unit I32 near the bottom of the vessel the current to which is controlled by a thermostat I34 immersed in the oil in the vessel I28. Thus, dry air at any desired temperature, depending upon the temperature for which the thermostat I34 is set, may be passed inside the casing through the pipe H8 and allowed to pass up into the treating chamber I00. Below the air pipe H8 is a partial partition I36 extending from the front of the casing to a point I38 where it stops, leaving a passage I40 by which hot vaporladen air may pass up into the chamber I00 along with the air from the pipe I I8. I-Iot vapor-laden air is generated in the bottom of the casing in much the same manner as in the apparatus first described. I42 is a thermostat by which the supply of current to an electric immersion heating unit I44 is controlled. A pipe I 46 similar to 50 having a control valve I48 leads to a series of pipes I50 similar to the pipes 54 but, instead of being completely immersed in the water, are only about half submerged, the water level being indicated at I52 which'may be observed in a water glass I54 atthe front of the casing. A drain cock I56 is provided in the bottom of the casing and a water supply pipe I58 is connected with means, such as a chicken-feed apparatus, for maintaining the water at the proper level.

By the apparatus last described, the relative humidity of the atmosphere in the sole-treating chamber I00 may be varied and controlled. By opening the valve l24 and/or closing the valve I48 and/or increasing the temperature of the air entering at l B, the relative humiditymay be decreasedf and by open-ing the valve I48 and/or closing the valve I24 and/or decreasing the tem-.- perature of the air entering at l l 8" the relative humidity'may be increased. The thermostat 134 provides means for maintaining the-*hot dry air at the desired temperature and the thermostat I 42 provides means for maintaining the hot vapor laden air at the desired temperature. The temperature of the mixture, as indicated bythe thermometer H4", may-be variedby adjustment ofeither orboth thermostats.- Thus, the opti-' mum conditions for practicing the present method may be obtained.

It is common practice in the cement attachquired to activate the cement, providing a shoe" having rubber-like cement thereon, and attachingthesole-t'othe 'shoe. t AlLThat improvement in methods of attaching soles toshoes which consists in roughing the overlasted upper of a shoe and the marginal portion of the. attaching face of a sole and applying polymerized chloroprene cement thereto, allow ing the cement to dry for an hour or more, then subjecting the sole to the action of hot air laden Withwater-vapor at a temperature of between 154 and'172 F. for a brief interval 0n the order of twenty seconds to activate the cement and render the sole inert, thenplacing the cemented ing of soles, prior to the operation of sole; at-

taching, to mold or conform the outsoletoa shape substantially like that of the shoe bottom to which it is to be attached. Before conforming or molding, the outsoles are-dipped in water to softenthem to such a condition that they will readily assume the required shape under pressure. With the solvent application process, it is necessary, in order to avoid an extra operation of wetting the soles; to keep such tempered soles in a humidified atmosphere from the time they are conformed or molded until they are ready for sole attaching. In practicing the method of this invention, it is not necessary that the soles be kept in a humidified atmosphere after they have been molded or conformed. It is preferred that these soles should come to the sole-attachingoperation in a substantially dry condition. If such outsoles contain fairly large quantities of moisture, there .is great danger in the sole-attaching process of marking the soles by reproducing on the outer face of the sole the irregularities of the shoe bottom, such as staples and nail heads when used. If the outsole in a substantially dry condition is treated by the apparatus disclosed, the

shoe bottom, after attachment, will show a soles to shoes which consistsin subjecting asole which is insufiiciently in temper to be inert and is cementedwith rubber-like cement insoluble in water to the action of hot air laden withpwaterallowing the major portion of the cement solvent to evaporate, then subjecting the sole to the action of hot air laden with water-vapor free from condensed moisture to activate the cement and render the sole inert, then placing the cemented surfaces of the shoe and sole in juxtaposition, and applying sole-attaching pressure.

3. That improvement in methods of attaching soles to shoes which consists in applying synthetic rubber-like cement to an outsole, allowing it to dry to an inactive condition, subjecting the sole to a current of air laden with dry watervapor, the temperature being high enough to activate the cement and the vapor content being suf- V ficient to render thesole inert in the time reareas of the shoe and sole in juxtaposition, and applying pressure to the shoe and sole'for a time sufficient to shape the inert sole to the contour of the shoebottom'and to cause coalescence between the" cemented surfaces to effect a permanent bond between the shoe and sole.

5. That improvement in methods of attaching soles to shoes which :consists 'in roughing the overlasted upper of a shoe and the marginal portion of the attaching face of a sole and applying ing the cement to dry, then subjecting the sole to the action of hot air laden with water-vapor at a temperature of about 158 F. for a brief interval sufiicient to activate the cement and render the sole inert, then placing the. cemented areas of the shoe and sole in juxtaposition, and applying pressureto the shoe and sole to shape the inert sole to the contour of the shoe bottom and to eiiect a permanent bond between the shoe and of air laden with water-vaporv at a temperature and for a time sufficient to activate the cement and render the sole inert, then placing the cemented areas of the shoe and sole in juxtaposition, applying pressure to the shoe and sole to shape the inert sole to the exact contour of the shoe bottom and to effect a permanent bond between the sole and shoe, and after a brief interval releasing the pressure.

7. The method of attaching a leather outsole to a shoe upper which comprises applying to the attaching surface of a leather outsole a cement insoluble in water and which may be activated attemperatures in the neighborhood of 154 F. to 172 F., permitting said cement substantially to dry, and, while the leather of said outsole is insufficiently in temper to render it inert, sub! jecting said outsole to a water- -vapor-laden atmosphere at a temperature in the neighborhood of 154 F. to 172 F. for a time sufficient simultaneou'sly to activate the cement and render the sole inert, and immediately bringing said outsole into juxtaposition with a shoe upper whose attaching surface is provided with a layer of cement, and pressing the outsole and shoe upper firmly together.

-8. The method of attaching a leather outsole to a shoe upper which comprises applying a solution ofjpolymerized chloroprene to the attaching surface of a leather outsole, allowing the major portion of the solvent to evaporate, and, while the leather of said outsole is insufficiently in temper to render it inert, subjecting said outsole to a water-vapor-laden atmosphere at a temperature in the neighborhood of 154 F. to 172 F. for a time sufficient simultaneously to activate the polymerized chloroprene and render the sole inert, and immediately bringing said outsole into juxtaposition with a shoe upper whose attaching surface is provided with a layer of polymerized chloroprene, and pressing the outsole and shoe upper firmly together.

9. The method of attaching a leatheroutsole to a shoe upper which comprises applying a solution of polymerized chloroprene to the attaching surface of a leather outsole, allowing the major portion of the solvent to evaporate, providing an atmosphere which is laden with water vapor to the extent of 50% to 100% relative humidity, which has a heat content of from 200 to 700 B. t. u. per pound of dry air and which is at a temperature in the neighborhood of 140 F. to 206 F., subjecting said outsole to such atmosphere for a time sufficient to activate the cement,

immediately bringing said outsole into juxtaposition with a shoe upper whose attaching surface is provided with a layer of polymerized chloroprene, and pressing the outsole and shoe upper firmly together. I

10. The method of attaching a leather outsole to a shoe upper which comprises applying a solution of polymerized chloroprene to the attaching surface of a leather outsole, allowing the major portion of the solvent to evaporate, providing an atmosphere which is laden with water vapor, varying the relative humidity between 50% and 70%, the heat content between' 250 and 500 B. t. u. and the temperature of the treating atmosphere between 160 and 200.F. to produce the optimum conditions for tempering the sole and activating the cement, subjecting said outsole to such atmosphere for a time sufficient to activate the cement and render the sole inert, immediately bringing said outsole into juxtaposition with a shoe upper whose attaching surface is provided with a layer of polymerized chloroprene, and pressing the outsole and shoe upper firmly together.

MAX W. 'I'E'ILOW. 

